Centering and holding unit for capping head

ABSTRACT

Containers ( 2 ) having a threaded neck ( 3 ) and a mouth ( 4 ) are capped by a unit ( 1 ) appearing as a carousel ( 5 ) equipped with capping heads caused to advance along a circular path (P) and capable of axial movement toward and away from the containers in such a way that each one can be fitted with a relative cap ( 11 ); each capping head of the unit ( 1 ) incorporates a gripper ( 31 ) furnished with two jaws ( 30 ) presenting relative conical surfaces ( 26 ), and respective cylindrical surfaces ( 27 ) designed to locate against the neck ( 3 ) of the container. When the cylindrical surfaces ( 27 ) register against the outer surface of the neck ( 3 ), the conical surfaces ( 32 ) are positioned with the lower edges ( 28 ) encroaching on the area compassed by the mouth ( 4 ) in such a way that the cap ( 11 ) can be gathered and aligned with the neck ( 3 ) of the container ( 2 ) before being tightened, thereby ensuring a precise fit.

This application is the National Phase of International ApplicationPCT/IB03/03454 filed Jul. 30, 2003 which designated the U.S. and thatInternational Application was published under PCT Article 21(2) inEnglish.

TECHNICAL FIELD

The present invention relates to a unit for capping containers.

In particular, the invention relates to a unit such as will apply a capincorporating a measure cup and drip catcher to the neck of eachcontainer.

BACKGROUND ART

Caps incorporating a measure cup and drip catcher are fashionedgenerally with a grippable portion of substantially cylindrical shape,terminating at the bottom in a screw collar enlarged to a diametergreater than that of the grippable portion and threaded internally insuch a way that it can be coupled releasably with the threaded neck of arespective container. The cap also presents a cylindrical tubularelement disposed concentrically with the screw collar and smaller indiameter. The cylindrical tubular element is accommodated in part by thecap, to which it is anchored, combining thus with the inside of thegrippable portion to provide a cup that can be used to measure out theproduct in the container. The part of the cylindrical element thatprojects axially from the cap and beyond the free edge of the screwcollar is insertable into the mouth of the container with a rectilinearmovement, and the cap thereupon advanced to the point at which theinternal thread of the collar can be coupled with the external thread ofthe neck. The diameter of the tubular element will generally match thediameter presented by the mouth of the container and, accordingly, theinsertion step calls for a certain degree of accuracy, obtained bypositioning the container and the relative cap in such a way that themouth and the tubular element are in faultless axial alignment one withanother.

Capping units of the type in question generally comprise a main carouselrotatable about a vertical axis and carrying a plurality of cappingstations spaced apart at identical angular distances around the axis.Each capping station comprises a capping head equipped with a gripperdevice designed to close around the collar of the cap, and is capable ofaxial movement along a second axis toward and away from a position ofengagement with a relative container, in which the cap is tightened onthe neck by the capping head. The main carousel is supplied with asuccession of containers, each presenting a body and a filler mouth,received from a first rotary infeed conveyor by way of a first transferstation, and a succession of caps entering by way of a second station.

During operation, the capping heads orbit about the vertical axis of thecarousel, each also moving axially toward the neck of a relativecontainer in such a way as to direct the tubular element into the mouth.The head then describes a controlled rotation about its own axis in sucha way as to screw the cap onto the container, whereupon the cappedcontainers are directed onto a second outfeed conveyor by way of a thirdtransfer station.

During the operation of inserting the caps and securing them to thecontainers, the containers rotate as one with the respective gripperdevices about the axis of the carousel, the object being to keep them inthe correct capping position, with the mouth aligned substantiallybeneath the respective capping head. To this end, the containers areaccommodated by a plurality of pockets afforded by the base of thecarousel.

Among the drawbacks encountered with machines of the type in question isthe fact that, although the carousel, the capping heads and the variousmechanical and drive components are all suitably dimensioned, it happensthat play will develop ultimately in the system due to wear on movingparts, and exact coaxial alignment between the capping head and themouth of the respective container can be lost. This leads todifficulties in assembling the cap correctly with the neck of thecontainer, causing the capping line to jam and forcing stoppages of themachine. The problem is particularly acute where the caps utilized areof the type incorporating a measure cup and drip catcher.

The object of the present invention is to provide a relativelyeconomical capping unit ensuring long-term reliability, such as will beunaffected by the aforementioned drawbacks and capable of fitting capsto respective containers automatically.

DISCLOSURE OF THE INVENTION

These objects and others besides, which will emerge more clearly fromthe following specification, are substantially realized in a unit forcapping containers comprising a plurality of capping devices movablealong a predetermined path toward and away from the containers forfitting caps to respective containers during a passage when each cappingdevice advances along at least one portion of the path accompanied by arelative container, the unit comprising gathering and aligning means,associated and operating in conjunction with each capping device, forgathering and aligning the cap with the neck of the container; whereinsaid gathering and aligning means comprise at least one first gatheringand aligning element comprising a frustoconical surface, convergingtoward the container, and a cylindrical surface, positionable in directcontact with the container; said frustoconical surface having a loweredge protruding internally of the area compassed by the mouth of thecontainer at least when the cylindrical surface is in a locatingposition.

The invention will now be described in detail, by way of example, withthe aid of the accompanying drawings, in which:

FIG. 1 illustrates a unit for capping containers, viewed schematicallyand in plan;

FIG. 2 illustrates a portion of the capping unit in FIG. 1, viewedschematically in a side elevation;

FIG. 2 a is an enlarged detail of FIG. 2;

FIG. 3 illustrates a detail of the capping unit in FIG. 1, viewedschematically and in plan;

FIGS. 4 and 5 illustrate a detail of the capping unit in FIG. 1, viewedschematically in perspective and shown in two different operatingpositions.

Referring to FIG. 1 of the drawings, 1 denotes a unit, in its entirety,for capping containers 2 each presenting a neck 3 and a filler mouth 4(see also FIGS. 2, 2 a, 4 and 5).

The machine 1 comprises a main carousel 5 rotatable about a verticalaxis 6, turning anticlockwise as viewed in FIG. 1, onto which containers2 are directed singly and in succession by way of a first transferstation 7, from a first rotary infeed conveyor 8.

The infeed conveyor 8 is rotatable about an axis 9 parallel to thevertical axis 6 of the carousel, turning clockwise as viewed in FIG. 1,taking up containers 2 singly and in succession from a respective infeedstation not shown in the drawings. The carousel 5 also presents a secondinfeed station 10 to which caps 11 are supplied singly and in successionby a second rotary conveyor 12 rotatable about a respective axis 13parallel to the axis 6 of the carousel and turning clockwise as viewedin FIG. 1.

The carousel 5 is positioned and shaped in such a way as to support thecontainers 2 internally of respective radial pockets 14 open on theoutward facing side and equispaced around the periphery, and carries aplurality of capping devices (FIG. 2) likewise equispaced angularlyaround the periphery.

Each of the capping devices 15, which are of conventional type and notillustrated in their entirety, comprises a capping head 16 ofconventional type (FIG. 2), not illustrated in detail, equipped with agripper device 17 by which the cap 11 can be clamped; the gripper device17 is also indicated schematically in FIG. 1.

In addition, each capping head 16 is capable of axial movement along arespective axis 18 extending parallel to the axis 6 of the carousel 5,generated cyclically toward and away from a position of engagement witha relative container 2, in which the cap 11 is applied to the neck 3 ofthe selfsame container 2.

As discernible from FIGS. 2, 2 a, 4 and 5, the single cap 11 is of thetype having a measure cup and drip catcher and comprises a grippableportion 19, of substantially cylindrical appearance as a rule,terminating at the bottom in a screw collar 20 of which the diameter isgreater than the diameter of the grippable portion 19.

The collar 20 is threaded internally in such a way that it can becoupled releasably with the threaded neck 3 of a respective container 2.Also forming part of the cap 11 is a cylindrical tubular element 21disposed concentrically with the screw collar 20, of which the diameteris smaller than the diameter of the selfsame collar 20. The cylindricaltubular element 21 is accommodated in part by the cap 11, to which it isfixed in such a way as to combine with the inside of the grippableportion 19 in providing the aforementioned cup that can be used tomeasure out the product in the container 2.

The portion 22 of the cylindrical element 21 that projects axially fromthe cap 11 and beyond the free edge 23 of the screw collar 20 isinsertable into the mouth 4 of the container 2 with a rectilinearmovement, whereupon the cap will be advanced to the point at which theinternal thread of the collar 20 can be coupled with the external threadof the neck 3 by the action of the respective capping head 16.

In general, the diameter of the tubular element 21 will match theinternal diameter of the mouth 4, with a small clearance allowed.

During the rotation of the carousel 5, the capping heads 16 and therelative gripper devices 17 revolve around the axis 6 of rotation of thecarousel 5 together with the containers 2 positioned in the pockets 14,following a predetermined feed path P.

As discernible from FIGS. 1, 2 and 3, the carousel 5 comprises a set ofgathering and alignment means denoted 24 in their entirety, associatedwith each capping device 15 and therefore with each gripper device 17,such as will provide a positional reference for the cap 11 when directedtoward the mouth 4 of the container by the capping head 16 andultimately align the cap 11 with the mouth 4, thereby eliminating anypossible errors of alignment attributable to wear on the moving parts ofthe carousel 5.

In particular, referring to FIGS. 4 and 5, the gathering and alignmentmeans 24 comprise two gathering and aligning elements 25 each affordinga first chute-like surface 26 angled convergently toward a relativecontainer 2, and a second locating surface 27 designed to registeragainst a part of the container 2.

In particular, the second surface 27 is intended to locate against theexternally threaded surface of the neck 3.

Referring to FIGS. 2 a, 4 and 5, when the two locating surfaces 27register against the neck 3, the lower edge 28 of the first chute-likesurface 26 lies within the area compassed by the mouth 4 of thecontainer.

In effect, the locating surface 27 is positioned immediately beneath thechute-like surface 26 and distanced farther from the axis 29 of thecontainer neck 3 than the lower edge 28 of the chute-like surface 26,which conversely encroaches on the area compassed by the mouth 4 of theneck 3.

In greater detail, the gathering and aligning elements 25 function asthe jaws 30 of a gripper 31 by which the cap 11 and the neck 3 of therelative container are gathered, restrained and aligned. The two jaws 30are capable of movement between a spread position (FIG. 4), allowing acontainer 2 to be inserted into the relative pocket 14 and aligned withthe relative capping head 15, and a closed position in which the jaws 30are in mutual contact, with the respective locating surfaces 27 againstthe neck 3 on either side, and the lower edges 28 of the chute-likesurfaces 26 occupying the space compassed by the mouth 4 of the neck 3,so that the cap 11 can be gathered and aligned with the neck 3.

More exactly, the aforementioned first chute-like surface 26 of each jaw30 consists in a frustoconical segment 32, and the second locatingsurface 27 consists in a cylindrical segment 33.

The two jaws 30 are mounted to respective pivots 34 and compriserespective arms 35 furnished with mechanical connection means 36. Themeans 36 in question are embodied as a pair of toothed sectors 37designed to mesh one with another in such a way that a movement of onejaw 30 will cause both of the jaws to operate in concert.

In addition, the two jaws 30 are interconnected by an elastic elementsuch as a coil spring 38, by which they are biased toward the spreadposition.

Observing FIG. 5, it will be seen that when the jaws 30 are in theclosed position, the step of gathering the cap 11 and aligning it withthe neck 3 is facilitated by the fact that the frustoconical segments 32and cylindrical segments 33 of the first and second surfaces are broughttogether to form a continuous frustoconical surface and a continuouscylindrical surface, with the exception of a gap presented by the partof the gripper 31 nearer the connection means 36.

As discernible from FIGS. 1 and 3, one of the jaws 30 interacts with acam profile 39 extending along the feed path P. In particular, theprofile 39 presents three segments, arranged in succession andconsisting in: a first closing segment 40 engaged slidably by the heel41 of the jaw 30 lying upstream relative to the direction of therotation of the carousel 5, in such a way that the jaws 30 can berotated into the closed position through the agency of the toothedsectors 37 (FIG. 5); a second segment 42 along which the jaws 30 of thegripper 31 are maintained in the closed position; and a third segment 43along which the jaws 30 are returned to the spread position.

Once the jaws 30 are in the closed position, the cap 11 is directedtoward the container 2 by the relative capping head 16 and, in the eventof there being a measure of misalignment between the cap 11 and the neck3, the bottom edge of the tubular element 21 presented by the cap 11will slide against the frustoconical surfaces 26 of the jaws 30 and slipeasily into the mouth 4 of the neck 3. Once the tubular element 21 hasentered the mouth 4 of the container a given distance, the rotation ofthe carousel 5 will bring the aforementioned heel 41 of the jaw 30 ontothe third segment 43 of the cam profile 39 allowing the gripper 31 toopen through the agency of the two toothed sectors 37. With the jaws 30spread, the capping head 16 continues its descent toward the container 2to the point at which the screw collar 20 locates over the neck 3.Thereafter, the gripper 17 of the capping head 16 will rotate about itsaxis 18 to tighten the cap 11 on the neck 3 of the container.

1. A unit for capping containers with a neck and filler mouth,comprising a plurality of capping devices movable along a predeterminedpath toward and away from the containers for fitting caps to respectivecontainers during a passage when each capping device advances along atleast one portion of the path accompanied by a relative container, theunit comprising gathering and aligning means, associated and operatingin conjunction with each capping device, for gathering and aligning thecap with the neck of the container; wherein said gathering and aligningmeans comprise at least one first gathering and aligning elementcomprising a frustoconical surface, converging toward the container, anda cylindrical surface, positionable in direct contact with thecontainer; said frustoconical surface having a lower edge protrudinginternally of the area compassed by the mouth of the container at leastwhen the cylindrical surface is in a locating position.
 2. A unit as inclaim 1, wherein said gathering and aligning means comprise twogathering and aligning elements movable between a spread position,distanced one from the other and allowing a container to be positionedin alignment with a relative capping device, and a closed position inwhich the cap is gathered and aligned with the neck of the container. 3.A unit as in claim 2, wherein the cylindrical surface is positionedbeneath the frustoconical surface and is distanced farther from thecontainer neck than the lower edge of the surface.
 4. A unit as in claim2, wherein the gathering and aligning elements constitute two jaws of agripper gathering and clamping the cap and the neck of a respectivecontainer and for aligning one with another.
 5. A unit as in claim 4,wherein the two jaws are mounted to respective pivots and compriserespective arms furnished with mechanical connection means forinteracting in such a way that a movement of one jaw will have theeffect of operating both jaws.
 6. A unit as in claim 5, wherein the twojaws are interconnected by spring means for biasing the gathering andaligning elements toward the spread position.
 7. A unit as in claim 4,wherein the frustoconical surface and the cylindrical surface lierespectively contiguous one to another when the two jaws are in closedposition, for gathering and aligning the cap with the neck of thecontainer.
 8. A unit as in claim 4, wherein at least one of the jawsinteracts with a cam profile extending along the feed path.
 9. A unitfor capping containers with a neck and filler mouth, comprising aplurality of capping devices movable along a predetermined path towardand away from the containers for fitting caps to respective containersduring a passage when each capping device advances along at least oneportion of said path accompanied by a relative container, the unitcomprising gathering and aligning means, associated and operating inconjunction with each capping device, for gathering and aligning the capwith the neck of the container; wherein said gathering and aligningmeans comprise two gathering and aligning elements each comprising afirst chute-like surface angled convergently toward the container and asecond locating surface positionable in direct contact with thecontainer; each first chute-like surface presenting a lower edgepositionable internally of the area compassed by the mouth of thecontainer at least when the second surface is in the locating position;the locating surface being placed beneath the chute-like surface andbeing distanced farther from the container neck than the lower edge ofthe chute-like surface.
 10. A unit as in claim 9, wherein each firstchute-like surface presented by each of the two gathering and aligningelements is a frustoconical surface, and the second locating surface isa cylindrical surface.
 11. A unit as in claim 10, wherein thefrustoconical surface and the cylindrical surface lie respectivelycontiguous one to another when the two jaws are in closed position forgathering and aligning the cap with the neck of the container.